Secondary or storage battery.



J. P. CLARE.

SECONDARY DR STORAGE BATTERY.

APPLICATION FILED SEPT. 23, 1910.

Patented Feb. 13, 1912.

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JAMFS P. CLARE, OF STRATHAM, NEW HAMPSHIRE.

SECONDARY 0R STORAGE BATTERY.

Specification of Letters Patent.

Patented Feb. 13, 1912.

Application filed September 23, 1910. Serial No. 588,416.

To all whom it may concern:

Be it known that I, JAMES P. CLARE, of Stratham. in the county ofRockingham and State of New Hampshire, a citizen of the United States,have invented a new and useful Improvement in Secondary or StorageBatteries, of which the following is a full, clear, and exactdescription, reference being had to the accompanying drawings, forming apart of this specification, in explaining its nature. I

My invention relates especially to and is an improvement upon that classof storage.

or secondary batteries employing in the unit or element thereof a numberof independent porous plates carrying or holding active material incontact with electrodes placed adjacent said plates andbetween whichporous plates an exciting fluid or electrolyte is admitted from thechamber of the jar or vessel in which the porous plates and electrodesare contained. \Vhile a battery of this kind is usually effective adifficulty has been found to exist in that the active material duringthe operation of the battery will expand and escaping from between aplate and adjacent electrode will tend to follow the edges of the plateand plate adjacent to it and creep across to the next elect-rode causingshort-circuiting between positive and negative electrodes. In some casesthe active material will creep across the entire end of the element.Attempt has been made to prevent the initial escape of the activematerial from between the plates and electrodes by parts held againstthe edges of the plates. While this is effective in preventing suchescape yet this expedient is not wholly effective in that it tends to solimit the expansion of the expanding active material as to causefracture of the porous plates, these plates being ordinarily made offragile material.

The object of my invention is to prevent the short-circuiting abovereferred to by preventing the escaping active material from passingalong the edges of the plates and forming a connection betweenelectrodes and this, moreover, Without preventing the expansion of theactive material. As may be seen by reference to the drawings, Iaccomplish my object by so forming the edges of the porous plates thatin order for the escaping active material to pass from one plate. toanother it must pass over surfaces tending to direct the material awayfrom tact with the electrodes.

the edge of the adjacent plate over which it would ordinarily pass andthence abruptly back by an acutely formed edge over which the activematerial can hardly pass without the continuity of its passage beingbroken.

Referring to the drawings-Figure l is a View in perspective of anelement or unit embodying my invention. Fig. 2 is a cross section of theelement. Fig. 3 is an enlarged detail showing the edge formation of theporous plates forming a part of the element.

In the drawings 1 represents the porous plates. Between adjacent pairsof these plates or adjacent to single plates are electrodes 2. Betweenthe electrodes and adjacent plates is active material 3 which is borneby the plates and held by them in con- On their backs the porous platesare provided with ribs 4 which form not only an abutment for adjacentplates placed back to back, but form alsochannels containing theelectrolyte or exciting fluid. The porous plates and electrodes arebound between insulating plates 5 and held by any suitable binder 6. Asthus far described the element is one of a common type.

Referring now to the construction of the respective porous plates, .itwill be observed that each plate is provided along its edges with acurved surface 7 which extends from the extreme lateral point where theporous plate is tending to hold the active material against itselectrode, thence back from the plane of the electrode, thence outwardlyand inwardly in substantially a direction reverse to the direct line ofdirection between the electrodes combined in the element and.

thence back by a surface or edge 8, the surfaces 7 and 8 meeting andthereby forming a very abrupt or acute edge 9.

In the operation of the battery the active material escaping frombetween any orous plate and the electrode adjacent to 1t will tend tocree out over the surface 7 which by reason 0 the direction of itscurvature tends to start the escaping material in a direction away fromthe edge of the next adjacent porous plate and once having taken suchdirection it cannot turn back over the surface 8 without passing overthe abrut edge 9 and this it cannot do without brea 1ng.

The construction above described is the one I have found the mosteffective in practice although it is obvious that the 'copstructionmight be varied and good results obtained without departing from thespirit of my invention. The essential point would seemto reside not somuch in curving the edge of the plate but in the formation of the abruptedge over which the expanding material would have to'pass in order toform a connection between the combined electrodes. The fact, also, thatbefore encountering the abrupt or acute edge the expanding material isled in a direction away from the direct line of direction between thecombined electrodes is also of importance.

While the expedient shown is a very simpleandvefiective one it isespecially good also in that it does not prevent the escape of-theexpanding active material which, as

' said before, if prevented from escaping tends to fracture the porousplates: it only tends to take care of the escaping active materlal andprevent it from doing any harm.

Having thus fully described my invention,

I claim and desire to secure by Letters Patent 'of the United States 1.In a secondary or storage battery, the combination of porous plates,electrodes and active material, each of said porous plates along theedges thereof being formed to present an abrupt edge between said elec-'trodes and removed therefrom and from one another.

2. In a secondary or storage battery, the combination of porous plates,electrodes and active material, each of said porous plates along theedges thereof being formed to present between said electrodes surfacesangularly inclined with respect to one another and meeting in an abruptedge removed from said electrodes and from one another.

3. In a secondary or storage battery, the combination of porous plates,electrodes and active material,-each of said porous plates along theedges thereof being formed to present surfaces extending in directionsaway from the direct line of direction be tween said electrodes andterminating in an abrupt edge removed from said electrodes and from oneanother. A

4. In a secondary or storage battery, the combination of porous plates,electrodes and .active material, said porous plates being formed topresentalorig the edges thereof curved surfaces extending in asubstantially reverse direction to the direct line of direc- .tionbetween said electrodes with surfaces also angularly inclined withrespect to said curved surfaces and meeting the same in abrupt edgesremoved from said electrodes.

. JAMES P. CLARE. Witnesses:

GEORGE W. RAND, ARTHUR S. FRENCH.

